Also, I have to wonder how many non-technical people just will not be able to accept that bitcoin could work at all. If you don't understand the cryptography then you have to take it on faith that the system could work as designed. It's easy for them to brand bitcoin advocates as kooks (see "Time Cube").
Unfortunately its still not proofed if it works (NP=P) . So even the technical people cant be really sure
True, modern cryptography and hashing functions could have systemic issues such as a low-cost NP->P algorithm etc. But Bitcoin itself is properly hedged against this since much bigger and more powerful systems/organisations would have to deal with this problem before Bitcoin would. Also, in all likelihood if there were a weakness in these systems it wouldn't come about all of a sudden--rather there would gradually be results in academia, then applications of those results, then more results, etc. So there would be time to adapt.